Cerebral and somatic near-infrared spectroscopy monitors are commonly used to detect
tissue oxygenation in various circumstances. This form of monitoring is based on tissue
infrared absorption and can be influenced by several physiological and non-physiological
factors that can induce error in the interpretation. This narrative review explores
those clinical and technical limitations and proposes solutions and alternatives in
order to avoid some of those pitfalls.
Key Words
To read this article in full you will need to make a payment
Purchase one-time access:
Academic and PersonalOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Journal of Cardiothoracic and Vascular AnesthesiaAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study.Anesth Analg. 2007; 104: 51-58
- Review article: cerebral near-infrared spectroscopy in adults: a work in progress.Anesth Analg. 2012; 115: 1373-1383
- EACTS/EACTA/EBCP guidelines on cardiopulmonary bypass in adult cardiac surgery.Br J Anaesth. 2019; 123: 713-757
- Cerebral oximetry provides early warning of oxygen delivery failure during cardiopulmonary bypass.J Cardiothorac Vasc Anesth. 2002; 16: 204-206
- Cerebral oxygen desaturation predicts cognitive decline and longer hospital stay after cardiac surgery.Ann Thorac Surg. 2009; 87 (discussion 44-45): 36-44
- Using cerebral oximetry to prevent adverse outcomes during cardiac surgery.Perfusion. 2011; 26: 79-81
- Early diagnosis of superior vena cava obstruction facilitated by the use of cerebral oximetry.J Cardiothorac Vasc Anesth. 2011; 25: 1101-1103
- Cerebral Oximetry Monitoring to Maintain Normal Cerebral Oxygen Saturation during High-risk Cardiac Surgery: A Randomized Controlled Feasibility Trial.Anesthesiology. 2016; 124: 826-836
- The association between postoperative cognitive dysfunction and cerebral oximetry during cardiac surgery: a secondary analysis of a randomised trial.Br J Anaesth. 2019; 123: 196-205
- Randomized trial of near-infrared spectroscopy for personalized optimization of cerebral tissue oxygenation during cardiac surgery.Br J Anaesth. 2017; 119: 384-393
- Optimizing cerebral oxygenation in cardiac surgery: A randomized controlled trial examining neurocognitive and perioperative outcomes.J Thorac Cardiovasc Surg. 2020; (159:943-953.e3)
- Brain magnetic resonance imaging abnormalities after the Norwood procedure using regional cerebral perfusion.J Thorac Cardiovasc Surg. 2006; 131: 190-197
- (by)Near Infrared Spectroscopy Principles, Device Understanding and Data Clinical Interpretation.in: Prabhakar H Mahajan C Kapoor I Manual of Neuroanesthesia: The Essentials. CRC Press Taylor & Francis Group, Boca Raton, FL2017 (by)
- A Practical Approach to Cerebro-Somatic Near-Infrared Spectroscopy and Whole-Body Ultrasound.J Cardiothorac Vasc Anesth. 2019; 33: S11-S37
- Über Sichtbarmachung, Verlauf und chemische Kinetik der Oxyhämoglobinreduktion im lebenden Gewebe, besonders in der menschlichen Haut.Pflüger's Archiv für die gesamte Physiologie des Menschen und der Tiere. 1932; 229: 372-384
- The Oximeter, an Instrument for Measuring Continuously the Oxygen Saturation of Arterial Blood in Man.Rev Sci Instrum. 1942; 13: 434-444
- Noninvasive, infrared monitoring of cerebral and myocardial oxygen sufficiency and circulatory parameters.Science. 1977; 198: 1264-1267
- Cerebral hemodynamics during cardiopulmonary bypass in children using near-infrared spectroscopy.Ann Thorac Surg. 1993; 56: 1473-1477
- Factors associated with a low initial cerebral oxygen saturation value in patients undergoing cardiac surgery.J Artif Organs. 2017; 20: 110-116
- Cerebral oximetry for cardiac surgery: a preoperative comparison of device characteristics and pitfalls in interpretation.J Artif Organs. 2018; 21: 412-418
- Influence of patient variables and sensor location on regional cerebral oxygen saturation measured by INVOS 4100 near-infrared spectrophotometers.J Neurosurg Anesthesiol. 2003; 15: 302-306
- Association Between the Quantity of Subcutaneous Fat and the Inter-Device Agreement of 2 Tissue Oximeters.J Cardiothorac Vasc Anesth. 2019; 33: 2989-2994
- Tissue Oximetry and Clinical Outcomes.Anesth Analg. 2017; 124: 72-82
- Utility of near-infrared spectroscopy in the diagnosis of lower extremity compartment syndrome.J Trauma. 2000; 48 (discussion 399-401): 396-399
- Near-infrared spectroscopy identifies compartment syndrome in an infant.J Pediatr Orthop. 2007; 27: 311-313
- Acute compartment syndrome in a patient on extracorporeal support: utility of near-infrared spectroscopy.J Cardiothorac Vasc Anesth. 2011; 25: 836-837
- Combined Cerebral and Renal Near-Infrared Spectroscopy After Congenital Heart Surgery.Pediatr Cardiol. 2015; 36: 1173-1178
- Preoperative cerebral and renal oxygen saturation and clinical outcomes in pediatric patients with congenital heart disease.J Clin Monit Comput. 2019; 33: 1015-1022
- Intraoperative renal regional oxygen desaturation can be a predictor for acute kidney injury after cardiac surgery.J Cardiothorac Vasc Anesth. 2014; 28: 564-571
- Practical intravital two-photon microscopy for immunological research: faster, brighter, deeper.Immunol Cell Biol. 2010; 88: 438-444
- Characterization of the near infrared absorption spectra of cytochrome aa3 and haemoglobin for the non-invasive monitoring of cerebral oxygenation.Biochim Biophys Acta. 1988; 933: 184-192
- Near-infrared spectrophotometry of the brain in cardiovascular surgery.Thorac Cardiovasc Surg. 1998; 46: 167-175
- Quantification of concentration changes in neonatal human cerebral oxidized cytochrome oxidase.J Appl Physiol. 1991; 71 (1985): 1907-1913
- Measurement of cranial optical path length as a function of age using phase resolved near infrared spectroscopy.Pediatr Res. 1996; 39: 889-894
- A Monte Carlo investigation of optical pathlength in inhomogeneous tissue and its application to near-infrared spectroscopy.Phys Med Biol. 1993; 38: 1859-1876
- Optical pathlength measurements on adult head, calf and forearm and the head of the newborn infant using phase resolved optical spectroscopy.Phys Med Biol. 1995; 40: 295-304
- Near infrared spectroscopy.Br J Anaesth. 1999; 82: 418-426
- Measurements of optical pathlength using phase-resolved spectroscopy in patients undergoing cardiopulmonary bypass.Anesth Analg. 2007; 104: 341-346
- Cerebral hemoglobin and optical pathlength influence near-infrared spectroscopy measurement of cerebral oxygen saturation.Anesth Analg. 1997; 84: 1297-1305
- Cerebral oxygenation during warming after cardiopulmonary bypass.Crit Care Med. 1997; 25: 1655-1662
- Reevaluation of near-infrared light propagation in the adult human head: implications for functional near-infrared spectroscopy.J Biomed Opt. 2005; 10064032
- Quantification of cerebral hemoglobin as a function of oxygenation using near-infrared time-resolved spectroscopy in a piglet model of hypoxia.J Biomed Opt. 2005; 10024026
- Near-infrared spectroscopy in adults: effects of extracranial ischaemia and intracranial hypoxia on estimation of cerebral oxygenation.Br J Anaesth. 1994; 73: 503-506
- Review: Near infrared brain and muscle oximetry: from the discovery to current applications.J Near Infrared Spectroscopy. 2012; 20: 1-14
- Direct comparison between cerebral oximetry by INVOS(TM) and EQUANOX(TM) during cardiac surgery: a pilot study.Heart Lung Vessels. 2014; 6: 197-203
- Impact of extracranial contamination on regional cerebral oxygen saturation: a comparison of three cerebral oximetry technologies.Anesthesiology. 2012; 116: 834-840
- Extracranial contamination in the INVOS 5100C versus the FORE-SIGHT ELITE cerebral oximeter: a prospective observational crossover study in volunteers.Can J Anesth. 2016; 63: 24-30
- Extracranial Contamination of Near-Infrared Spectroscopy Devices.Anesth Analg. 2017; 124: 356-358
- Principles, techniques, and limitations of near infrared spectroscopy.Can J Appl Physiol. 2004; 29: 463-487
- Some factors affecting cerebral tissue saturation during obstructive sleep apnoea.Eur Respir J. 2002; 20: 444-450
- Noninvasive determination of the optical properties of adult brain: near-infrared spectroscopy approach.J Biomed Opt. 2004; 9: 221-229
- A proposed algorithm for the intraoperative use of cerebral near-infrared spectroscopy.Semin Cardiothorac Vasc Anesth. 2007; 11: 274-281
- Monitoring of brain function in anesthesia and intensive care.Curr Opin Anaesthesiol. 2010; 23: 759-764
- Evaluation of a cerebral oximeter as a monitor of cerebral ischemia during carotid endarterectomy.Anesthesiology. 2000; 93: 964-970
- The effectiveness of regional cerebral oxygen saturation monitoring using near-infrared spectroscopy in carotid endarterectomy.J Clin Neurosci. 2003; 10: 79-83
- Internal and external carotid contributions to near-infrared spectroscopy during carotid endarterectomy.Stroke. 1997; 28: 906-911
- Transesophageal echocardiography with the use of a four-millimeter probe.J Am Soc Echocardiogr. 1997; 10: 499-504
- A comparison of cerebral oxygenation as measured by the NIRO 300 and the INVOS 5100 Near-Infrared Spectrophotometers.Anaesthesia. 2002; 57: 999-1006
- Optical imaging of infants' neurocognitive development: recent advances and perspectives.Dev Neurobiol. 2008; 68: 712-728
- Factors affecting the performance of 5 cerebral oximeters during hypoxia in healthy volunteers.Anesth Analg. 2013; 117: 813-823
- Comparing near-infrared spectroscopy devices and their sensors for monitoring regional cerebral oxygen saturation in the neonate.Pediatr Res. 2013; 74: 557-563
- Cerebral oxygenation after birth - a comparison of INVOS((R)) and FORE-SIGHT near-infrared spectroscopy oximeters.Acta Paediatr. 2014; 103: 488-493
- Lateral frontal cortex oxygenation changes during translation and language switching revealed by non-invasive near-infrared multi-point measurements.Brain Res Bull. 2002; 59: 235-243
- Assessment of a noninvasive cerebral oxygenation monitor in patients with severe traumatic brain injury.J Neurosurg. 2014; 120: 901-907
- Arterial and venous contributions to near-infrared cerebral oximetry.Anesthesiology. 2000; 93: 947-953
- Near-infrared spectroscopy as an index of brain and tissue oxygenation.Br J Anaesth. 2009; 103: i3-13
- Cerebral arterial and venous contributions to tissue oxygenation index measured using spatially resolved spectroscopy in newborn lambs.Anesthesiology. 2010; 113: 1385-1391
- Validation in volunteers of a near-infrared spectroscope for monitoring brain oxygenation in vivo.Anesth Analg. 1996; 82: 269-277
- Cerebral venous and arterial blood volumes can be estimated separately in humans using magnetic resonance imaging.Magn Reson Med. 2002; 48: 583-588
- In vivo MR measurements of regional arterial and venous blood volume fractions in intact rat brain.Magn Reson Med. 2000; 43: 393-402
- Relative changes of cerebral arterial and venous blood volumes during increased cerebral blood flow: implications for BOLD fMRI.Magn Reson Med. 2001; 45: 791-800
- Influence of steep Trendelenburg position and CO(2) pneumoperitoneum on cardiovascular, cerebrovascular, and respiratory homeostasis during robotic prostatectomy.Br J Anaesth. 2010; 104: 433-439
- Effects of Changes in Arterial Carbon Dioxide and Oxygen Partial Pressures on Cerebral Oximeter Performance.Anesthesiology. 2018; 128: 97-108
- Assessment ofCerebral Autoregulation Patterns with Near-infrared Spectroscopy during Pharmacological-induced Pressure Changes.Anesthesiology. 2015; 123: 327-335
- Influence of adipose tissue thickness on near infrared spectroscopic signal in the measurement of human muscle.J Biomed Opt. 1996; 1: 418-424
- Influence of subcutaneous fat layer on muscle oxygenation measurement using NIRS.in: Proceedings of the Conference Influence of subcutaneous fat layer on muscle oxygenation measurement using NIRS. 1996: 37-45
- Adipose tissue thickness affects in vivo quantitative near-IR spectroscopy in human skeletal muscle.Clin Sci (Lond). 2001; 101: 21-28
- Point-of-Care Ultrasound to Evaluate Thickness of Rectus Femoris, Vastus Intermedius Muscle, and Fat asan Indicator of Muscle and Fat Wasting in Critically Ill Patients in a Multidisciplinary Intensive Care Unit.Indian J Crit Care Med. 2018; 22: 781-788
- Skin blood flow influences near-infrared spectroscopy-derived measurements of tissue oxygenation during heat stress.J Appl Physiol. 2006; 100 (1985): 221-224
- Skin blood flow affects in vivo near-infrared spectroscopy measurements in human skeletal muscle.Jpn J Physiol. 2005; 55: 241-244
- Cutaneous vasoconstrictionaffects near-infrared spectroscopy determined cerebral oxygen saturation during administration of norepinephrine.Anesthesiology. 2012; 117: 263-270
- Cerebral oxygen saturation assessed by near-infrared spectroscopy during coronary artery bypass grafting and early postoperative cognitive function.Ann Thorac Surg. 2002; 74: 109-114
- Changes in near infrared spectroscopy during deep hypothermic circulatory arrest.Ann Card Anaesth. 2009; 12: 17-21
- Interference of cerebral near-infrared oximetry in patients with icterus.Anesth Analg. 2000; 90: 489-493
- Utility of near infrared light to determine tissue oxygenation during hepato-biliary surgery.J Clin Monit Comput. 2015; 29: 613-619
- Laboratory variables associated with low near-infrared cerebral oxygen saturation in icteric patients before liver transplantation surgery.Anesth Analg. 2011; 112: 1347-1352
- Myoglobin oxygen dissociation by multiwavelength spectroscopy.J Appl Physiol. 1997; 82 (1985): 86-92
- Hemoglobin and myoglobin contributions to skeletal muscle oxygenation in response to exercise.Adv Exp Med Biol. 2011; 701: 347-352
- Estimated contribution of hemoglobin and myoglobin to near infrared spectroscopy.Respir Physiol Neurobiol. 2013; 186: 180-187
- Cerebral oxygenation measured by near-infrared spectroscopy: comparison with jugular bulb oximetry.Ann Thorac Surg. 1996; 61: 930-934
- [Regional transcranial oximetry with near infrared spectroscopy (NIRS) in comparison with measuring oxygen saturation in the jugular bulb in infants and children for monitoring cerebral oxygenation].Biomed Tech (Berl). 2000; 45: 328-332
- Regional cerebral oxygenation by NIRS does not correlate with central or jugular venous oxygen saturation during interventional catheterisation in children.Acta Anaesthesiol Scand. 2008; 52: 1370-1374
- Comparison of different near-infrared spectroscopic cerebral oxygenation indices with central venous and jugular venous oxygenation saturation in children.Paediatr Anaesth. 2008; 18: 160-166
- A comparison of two systems for assessing cerebral venous oxyhaemoglobin saturation during cardiopulmonary bypass in humans.Anaesthesia. 1993; 48: 697-700
- A comparison of near-infrared spectroscopy and jugular bulb oximetry in comatose patients resuscitated from a cardiac arrest.Anaesthesia. 1998; 53: 13-19
- Spatially resolved spectroscopy (NIRO-300) does not agree with jugular bulb oxygen saturation in patients undergoing warm bypass surgery.Can J Anesth. 2001; 48: 497-501
- The accuracy of a near-infrared spectroscopy cerebral oximetry device and its potential value for estimating jugular venous oxygen saturation.Anesth Analg. 2014; 119: 1381-1392
- Percutaneous catheterization of the jugular bulb with a Doppler probe: technical note.Neurosurgery. 1993; 33: 151-153
- Preoperative cerebral oxygen saturation and clinical outcomes in cardiac surgery.Anesthesiology. 2011; 114: 58-69
- Preoperative regional cerebral oxygen saturation is a predictor of postoperative delirium in on-pump cardiac surgery patients: a prospective observational trial.Crit Care. 2011; 15: R218
- Portal Hypertension Is Associated With Congestive Encephalopathy and Delirium After Cardiac Surgery.Can J Cardiol. 2019; 35: 1134-1141
- The significance of baseline cerebral oxygen saturation in children undergoing congenital heart surgery.Am J Surg. 2005; 190: 260-263
- Cerebral oximetry in dead subjects.J Neurosurg Anesthesiol. 1996; 8: 189-193
- Evaluation of post-mortem oxymetry with reference to the causes of death.Forensic Sci Int. 1997; 87: 201-210
- A Case of Persistence of Normal Tissue Oxygenation Monitored by Near-Infrared Spectroscopy (NIRS) Values Despite Prolonged Perioperative Cardiac Arrest.Am J Case Reports. 2019; 20: 21-25
- Near-infrared Spectroscopy Monitoring During Cardiac Arrest: A Systematic Review and Meta-analysis.Acad Emerg Med. 2016; 23: 851-862
- Cerebral Oximetry During Cardiac Arrest: A Multicenter Study of Neurologic Outcomes and Survival.Crit Care Med. 2016; 44: 1663-1674
- Deep hypothermic circulatory arrest during the arterial switch operation is associated with reduction in cerebral oxygen extraction but no increase in white matter injury.J Thorac Cardiovasc Surg. 2013; 146: 1327-1333
- Continuous cerebral hemodynamic measurement during deep hypothermic circulatory arrest.Biomedical Optics Express. 2016; 7: 3461-3470
- Intraoperative care for aortic surgery using circulatory arrest.J Thorac Dis. 2017; 9: S508-S520
- Near-infrared spectroscopy (NIRS) monitoring in contemporary anesthesia and critical care.Acta Anaesthesiol Belg. 2010; 61: 185-194
- Near-infrared spectroscopy in vegetables and humans: An observational study.Eur J Anaesthesiol. 2018; 35: 907-910
- Near infrared spectroscopy in brain injury: today's perspective.Acta Neurochir Suppl. 2005; 95: 453-457
- Frequency-domain vs continuous-wave near-infrared spectroscopy devices: a comparison of clinically viable monitors in controlled hypoxia.J Clin Monit Comput. 2017; 31: 967-974
- Regional cerebral oxygenation measured by multichannel near-infrared spectroscopy (optical topography) in an infant supported on venoarterial extracorporeal membrane oxygenation.J Thorac Cardiovasc Surg. 2011; 141: e31-e33
- Monitoring cerebral oxygenation during balloon occlusion with multichannel NIRS.J Cereb Blood Flow Metab. 2014; 34: 347-356
- Multiwavelength, wideband, intensity-modulated optical spectrometer for near-infrared spectroscopy and imaging.in: Proceedings of the Conference Multiwavelength, wideband, intensity-modulated optical spectrometer for near-infrared spectroscopy and imaging. 1993: 248-257
- Portable, high-bandwidth frequency-domain photon migration instrument for tissue spectroscopy.Opt Lett. 1994; 19: 1934-1936
- Quantification in tissue near-infrared spectroscopy.Philosophical Transactions of the Royal Society B-Biological Sciences. 1997; 352: 649-659
- Clinical Determination of Tissue Optical Properties in vivo by Spatially Resolved Reflectance Measurements.in: Proceedings of the Conference Clinical Determination of Tissue Optical Properties in vivo by Spatially Resolved Reflectance Measurements. Munich, Optical Society of America, 2003: 5138-5196
- Clinical evaluation of time-resolved spectroscopy by measuring cerebral hemodynamics during cardiopulmonary bypass surgery.J Biomed Opt. 2007; 12062112
- Time domain functional NIRS imaging for human brain mapping.Neuroimage. 2014; 85: 28-50
- Stable tissue-simulating phantoms with various water and lipid contents for diffuse optical spectroscopy.Biomedical Optics Express. 2018; 9: 5792-5808
- Time-Domain Near-Infrared Spectroscopy and Imaging: A Review.Applied Sciences-Basel. 2019; 9: 1127
- Clinical Brain Monitoring with Time Domain NIRS: A Review and Future Perspectives.Applied Sciences. 2019; 9: 1612
- A clinical tissue oximeter using NIR time-resolved spectroscopy: Oxygen Transport to Tissue XXXVII.Springer, 2016: 427-433
- In vivo mitochondrial oxygen tension measured by a delayed fluorescence lifetime technique.Biophys J. 2008; 95: 3977-3990
- A monitor for Cellular Oxygen METabolism (COMET): monitoring tissue oxygenation at the mitochondrial level.J Clin Monit Comput. 2017; 31: 1143-1150
- A pilot study of exercise-induced changes in mitochondrial oxygen metabolism measured by a cellular oxygen metabolism monitor (PICOMET). Biochimica et biophysica acta.Molecular Basis Disease. 2019; 1865: 749-758
- Special article: measuring mitochondrial oxygen tension: from basic principles to application in humans.Anesth Analg. 2013; 117: 834-846
- Cutaneous Mitochondrial PO2, but Not Tissue Oxygen Saturation, Is an Early Indicator of the Physiologic Limit of Hemodilution in the Pig.Anesthesiology. 2016; 125: 124-132
- Comparing Doppler ultrasonography and cerebral oximetry as indicators for shunting in carotid endarterectomy.Anesth Analg. 2000; 91: 1339-1344
- Whole body ultrasound in the operating room and the intensive care unit.Korean J Anesthesiol. 2019; 72: 413-428
- Intracranial pressure and venous cannulation for cardiopulmonary bypass.Anesth Analg. 1999; 88: 329-331
- Cerebral Pulsatility Index Is Elevated in Patients with Elevated Right Atrial Pressure.J Neuroimaging. 2018; 28: 95-98
- Targeting optimal blood pressure monitoring: what's next?.J Thorac Dis. 2018; 10: S3281-S3285
- Patient management algorithm combining processed electroencephalographic monitoring with cerebral and somatic near-infrared spectroscopy: a case series.Can J Anesth. 2019; 66: 532-539
- Can we prevent significant brain desaturation during defibrillator testing by increasing the brain saturation reserve?.Can J Anesth. 2018; 65: 732-734
- A Proposed Approach to Cerebral and Somatic Desaturation in the Intensive Care Unit: Preliminary Experience and Review.J Cardiothorac Vasc Anesth. 2017; 31: 1805-1809
- Transcranial Doppler monitoring guided by cranial two-dimensional ultrasonography.Can J Anesth. 2017; 64: 885-887
- Cerebral ischemia during shoulder surgery in the upright position: a case series.J Clin Anesth. 2005; 17: 463-469
- Neuromonitoring Techniques: Quick Guide for Clinicians and Residents: Chapter 7 Near-Infrared Spectroscopy.Academic Press: Elsevier, San Diego2018: 179-233
- Cerebral near-infrared spectroscopy in adult heart surgery: systematic review of its clinical efficacy.Can J Anesth. 2005; 52: 79-87
- Cerebral near-infrared spectroscopy monitoring and neurologic outcomes in adult cardiac surgery patients: a systematic review.Anesth Analg. 2013; 116: 663-676
- Effects of cerebral near-infrared spectroscopy on the outcome of patients undergoing cardiac surgery: a systematic review of randomised trials.BMJ Open. 2017; 7e016613
- Intraoperative cerebral oximetry-based management for optimizing perioperative outcomes: a meta-analysis of randomized controlled trials.Can J Anesth. 2018; 65: 529-542
- Cerebral near-infrared spectroscopy (NIRS) for perioperative monitoring of brain oxygenation in children and adults.Cochrane Database Syst Rev. 2018; 1Cd010947
- Measurement of cerebral oxygen consumption in the human neonate using near infrared spectroscopy: cerebral oxygen consumption increases with advancing gestational age.Pediatr Res. 1998; 44: 283-290
- Quantification of adult cerebral hemodynamics by near-infrared spectroscopy.J Appl Physiol. 1994; 77 (1985): 2753-2760
- A comparison of the INVOS 4100 and the NIRO 300 near-infrared spectrophotometers.Anesth Analg. 2002; 94: 586-590
Article Info
Publication History
Published online: July 21, 2020
Footnotes
Abbreviations: ∆A, change in optical density; a, extinction coefficient of chromophore; A, light attenuation coefficient; B, path length factor; c, concentration of chromophore; cox, co-oximetry; CPB, cardiopulmonary bypass; DHCA, Deep Hypothermic Circulatory Arrest; HbO2, oxyhemoglobin; HHb, deoxygenated hemoglobin; L, length between light entry and exit; LDF, Laser-Doppler flowmeter; NIRS, near-infrared spectroscopy; nm, nanometer; rSO2, regional oxygen saturation; rScO2, regional cerebral oxygen saturation; SD, standard deviation; SjO2, jugular bulb oxygen saturation; SRS, spatially resolved spectroscopy; THb, total hemoglobin; tNIRS-1, tissue oximeter using time resolved spectroscopy; TOI, tissue oxygen index
Identification
Copyright
© 2020 Elsevier Inc. All rights reserved.
